Fluid lubricated planetary piston water pump



E. c. KIEKHAEFER 2,493,148

FLUID LUBRICATED PLANETARY PISTON WATER PUMP Filed Dec. 28. 1945 2 Sheets-Sheet 1 lmerclm'ekhaefez INVENTOR.

ATTORNEY E. c. KIEKHAEFER FLUID waazcmwrmnmmy rxswon wumn'rumr Filed Dec. 28 1945 7 Jan. 3, 1950 2 Sheets-Sheet 2 F g t h m K V Q w M E ATTORNEY.

Patented Jan. 3, 1950 FLUID LUBRICATED PLANETARY PISTON WATER PUMP v Elmer C. Kiekhaefer, Cedarburg, Wis.

Application December 28, 1945, Serial No. 637,523

1 Claim. 1

This invention relates to a water pump for outboard motors and the like.

The invention has been applied to the construction of water pumps having a cylindrical chamber through which the propeller shaft passes concentrically and in which a resilient oscillating element is mounted on an eccentric on the shaft and thereby oscillated around the chamber in a peripheral direction from the inlet ports to the outlet ports, the resilient element being held against rotation and substantially sealed against the outer chamber wall in the region immediately between the adjacent inlet and outlet ports.

One of the objects ofthe present invention is to provide a pump in which the eccentric is self lubricated within the resilient element.

Another object of the invention is to provide a seal between the resilient element and the peripheral wall of the chamber without requiring a boss or projection on either, thereby reducing machining costs.

Another object is to provide a movable sealing element separate from both the chamber housing and the resilient element and which floats relative thereto in a pivotal manner to more effectively seal the pump and guide the resilient element without distortion of the latter.

Other objects and advantages of the invention are set forth in the description of an embodiment of the invention illustrated in the accompanying drawing.

In the drawing:

Figure 1 is a detail vertical section taken axially of a propeller shaft at the lower end of an outboard motor and showing the pump in section;

Fig. 2 is an enlarged transverse section through the pump showing the impeller element in the position of nearly complete discharge and maximum intake in a single cycle;

Fig. 3 is similar to Fig. 2 showing the impeller element in the position immediately after closing the intake and opening the outlet;

Fig. 4 is a similar position showing the impeller element about halfway in its stroke, where it is both discharging and filling the chamber;

Fig. 5 is a perspective view of the impeller;

Fig. 6 is a perspective view of the pivot block;

Fig. '7 is a transverse section sim-iiar'to Fig. '4 showing a modified form of pivot block; and

rig. 8 is a view similar to Fig. '1 showing another modified form of pivot block.

The lower housing of the outboard motor of a propeller shaft 4 which extends forwardly into the housing I and is supported therein by a front needle bearing 5 and a main bearing 6. A beveled gear I is keyed to shaft 4 between bearings 5 and 6 and meshes with a corresponding drive gear 8 on the lower end of the vertical drive shaft 9. The casing for bearing 6 has a cylindrical skirt l0 extending rearwardly from housing I between the housing and the propeller hub, and which constitutes the outer peripheral wall of the pump chamber.

The front wall ll of the pump chamber is the smooth transverse rear face of the casing for hearing 6.

The rear wall l2 of the pump chamber is the smooth cover plate which is positioned in the outer end of wall I0 and held in place by the split ring l3 fitting into a groove in the inner surface of the wall It).

The inlet to the pump chamber is through a plurality of closely adjacent ports 14 in the wall l0 extending radially of the pump.

The outlet from the pump chamber is through a single large passage l5 upwardly through the wall Ill.

The propeller shaft 4 passes axially through the pump chamber and has an eccentric cam sleeve l6 keyed thereto to rotate therewith in the chamber.

The impeller I! for the pump is a resilient generally cylindrical element, preferably of reinforced rubber, fitted closely upon the cam l8 and having an outer diameter substantially smaller than the inner diameter of the peripheral wall H), with a radial thickness approximating the radial distance between the wall l0 and the highest point of cam IS.

The axial length of impeller I1 is equal to the distance between the front wall H and rear wall 12 of the pump chamber to seal the pump against leakage along these surfaces.

The impeller is cut through radially to provide a radial slide way It for receiving a pivotal guide block l9 mounted on a pivot pin 20, the ends of which are loosely held in recesses 2| in the corresponding rear and front walls H and has a horizontal cylindrical portion merging generally with the circular hub 2 of the propeller 3. The propeller 3 is mounted on the rear end I2 of the pump chamber.

The slide way l8 extends for the full length of impeller l1 and from the outer periphery of the impeller to the eccentric sleeve [6, and provides two passages between impeller I I and block I9 which is lubricated by the fluid being pumped and serves to conduct fluid to and from the sleeve It for lubricating the latter and carrying away any foreign abrasive material between the bearing surfaces of sleeve l6 and the impeller. For this purpose the pivot block 19 should fit relatively loosely in the slide way Ill.

The pivot block I!) seals against the front and rear walls ll and I2 of the pump chamber and has a width approximating the width of guideway III in the impeller H.

The radial thickness of pivot block I! should be less than the radial thickness of impeller l1 and the outer surface of the block is shaped to engage and seal against the inner surface of wall I at all times.

For this purpose the pivot block l9, as shown in Figs. 2, 3, 4 and 6 has a curved outer surface 22 formed concentric with the axis of pin 20 so that as the block turns from side to side in response to the oscillations of impeller [1 the curved surface of the block rubs over the inner surface of wall 10 and maintains a constant sealing contact therewith.

The pivot block is is preferably constructed of rubber to resist wear and may have a metal casing 23 of U-shape disposed as an insert between the block and the impeller to provide the desired metal to rubber contact for easy sliding between the same.

The pivot block IQ of Fig. 7 has three small thin V flexible radial edges 24 which press edgewise against the inner surface of wall l0 to seal the pump in operation.

The pivot block IQ" of Fig. 8 is of metal and has a triangularly shaped rubber insert 25 secured in a recess in itsouter surface and providing a thin rubber edge bearing against the inner surface of wall ill of the pump chamber.

The block I9 is disposed between the inlet ports I! and the outlet passage l5 for the pump, the ports I4 and passage l5 being located near each other and on opposite sides of block l9 to provide maximum capacity for each cycle of the pump in operation. 7

The operation of the pump is illustrated in Figs. 2, 3 and 4, which show the successive positions of the impeller I1 with the shaft 4 turning in a clockwise direction. Operation of the shaft 4 in a counter-clockwise direction would result in a reversal in the flow of fluid therethrough.

As the impeller l1 moves around the chamber in response to the turning of cam it it tilts the pivot block 19 from side to side and causes the outer surface 22 or the edges 24 or insert 25, as the case may be, to wipe the inner surface of wall l0 and to constantly maintain a self-lubricated sealing contact therewith.

The invention may have various embodiments within the scope of the accompanying claim.

I claim:

In a pump of the class described having 9. casing comprising a cylindrical wall and end closures providing a pump chamber with circumferentially spaced inlet and outlet ports, a rotary shaft extending axially through the casing and having an eccentric on the outer surface thereof within the pump chamber, an impeller bearing on said eccentric and disposed between said eccentric and outer casing wall and adapted to gyrate about the pump chamber in response to the rotation of said shaft, said impeller being constructed of resilient wear resistant material in the form of a ring having a radial slot therein extending for the full radial thickness of the ring to said eccentric, and said ring extending axially from end to end of said casing and having a radial thickness substantially equal to the radial distance between the highest part of said eccentric and the casing wall, and a tiltable guide block pivotally secured to the casing and sealed against the casing wall between the inlet and outlet ports and extending substantially loosely within the slot in said ring to provide for lubrication of the bearing surfaces between the impeller and eccentric and end closures by the liquid being pumped.

ELMER C. KIEKHAEFER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,591,030 Finch July 6, 1926 1,959,904 Cornell May 22, 1934 2,227,740 Friedell et a1. Jan. 7, 1941 FOREIGN PATENTS Number Country Date 9,808 Germany 1878 

